The ability to directly and uniformly immobilize proteins onto detection surfaces in a robust and simple way, with full retention of biological activity is a highly coveted goal in the field of bioengineering. It leads to the development of high value devices and applications which will have a tremendous impact on basic research, drug discovery, diagnostics and biodetection. An excellent way to achieve this is to use the property of known gold binding peptides to strongly adhere to gold surfaces under very mild binding conditions and to covalently attach any desired target protein to such peptides by recombinant means. The specific aims of this proposal are: a) to test the feasibility of producing gold binding peptides in Escherichia coli as fusion proteins with molecules of biological and commercial relevance such as protein A and streptavidin; b) to optimize the expression and purification conditions; c) to characterize and optimize gold binding of the fusion proteins; d) to construct and characterize biosensors with these recombinant fusion proteins. The long-term aim of this project is to expand the expression capabilities to a host of other molecules of biological and commercial significance and develop biosensing devices and assays for a wide variety of applications of considerable commercial potential.